Whirley,
I think you should go ahead and put the 46 in it. Is this your first plane? When I was learning, there were a couple times that I would have cracked up the plane had I not had the extra power that the .46 could provide. If you stall, want to pull out of a bad landing, whatever, the 46 really made the plane jump when you needed it to. Oh well have fun either way, but when you do put the 46 on it, you will be wishing it had been there all along.

Here's a couple pic's of mine

engine in lower left is original 40 la that came with it, never saw the air with that engine.